Light emitting diodes (LEDs) are often used to indicate the operational status of circuitry. LEDs are generally small and often mounted on circuit boards or electronic modules within an electromagnetic compliant (EMC) enclosure. In some applications, an EMC faceplate shields the LEDs from sight. However, EMC faceplates can have bores, or openings, that have diameters less than predetermined values without affecting the EMC properties of the enclosure.
Light pipes are sometimes used to transfer the light emitted by the LEDS to a viewable surface that is external to the EMC enclosure. The light pipes pass through the bores of the faceplate. As such, the diameter of the light pipe is constrained by the predetermined maximum bore diameter that does not degrade the EMC properties. This diameter can be a few millimeters or less, depending on the specific EMC requirements and the enclosed circuitry. As such, the viewing surface outside the enclosure typically does not exceed a few millimeters and is therefore difficult to see. Often light from one light pipe couples, or “bleeds”, into one or more neighboring light pipes through the structure used to fix the light pipes to each other. Thus, if only one LED is on, neighboring light pipes can also receive some of the light emitted from the active LED at their respective endfaces, thereby making it difficult to determine the status of the circuitry. Additionally, if the LEDs generate different color light, the light from LEDs of neighboring light pipes can reduce the visibility at the endface of a given light pipe.
What is needed is a device for conducting light through an electromagnetic compliant faceplate that is not limited in size by EMC requirements and reduces the bleeding of light into neighboring light pipes. The present invention satisfies this need and provides additional advantages.